Automatic electromagnetic circuit-breaker



2 Sheets-Sheet 1.

(No Model.)

W. B. HARRINGTON.

AUTOMATIG ELECTROMAGNETIC CIRCUIT BREAKER.

Patented Mar. 23,18 7.

Q ATTORNEY.

INVENTOR WITNESSES (No Model.) 2 Sheets-Sheet 2 W. E. HARRINGTON.AUTOMATIC ELECTROMAGNETIC CIRCUIT BREAKER.

No. 579,431. Patented Mar. 23, 1897.

UNITED STATES PATENT CEEieE.

IV ALTER E. HARRINGTON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THECUTTER ELECTRICAL it MANUFACTURING COMPANY, OF NElV JERSEY.

AUTOMATIC ELECTROMAGNETIC ClRCUlT BREAKER.

SPECIFICATION forming part of Letters Patent No. 579,481, dated March23, 1897.

Application filed May 5, 1896.

To aZZ whom it; may concern:

Be it known that I, \VAL'IER E. HARRING- TON, a citizen of the UnitedStates, residing in the city and county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inAutomatic Electromagnetic Circuit-Breakers, of which the following is aspecification.

My invention relates to automatic electromagnetic circuit-breakers; andthe chief objectsof my improvements are to provide a circuit-breakerwhich will operate to open or close a circuit in a space of time ininverse ratio to the volume of excessive current passing through it,which will be actuated either to open or close a circuit aspredetermined, which will be actuated either upon a prede terminedmaximum or minimum flow of current, and in which the force exerted uponone of the movable cores by normal flow of current may be employed tokeep the switchbridge in position desired. I attain these objects by themechanism illustrated in the accompanying drawings, in which-- Figure 1is a front view of one form of my magnetic circuit-breaker withswitch-bridge pivoted to magnetic jacket. Fig. 2 is a side sectionalview of same on lines as or of Fig. 1. Fig. 3 is a front view of aportion of another 0 form of my circuit-breaker, showing switchbridgenot pivoted to magnetic jacket. Fig. i is a side view of a portion of mymagnetic circuit-breaker constructed to close the circuit or make ashort circuit upon a predeter- 3 5 mined maximum or minimum flow insteadof opening it. Fig. 5 is a side sectional view of portions of magneticjacket, coil, and nonmagnetic tube, showing magnetic rin at up per endof non-magnetic tube. Fig. (3 is a sec- 0 tional view of a portion ofcircuit-breaker, showing another form of movable core. Fig. 7 is a viewof a portion of circuit-breaker, showing core D pivoted to armindependent of that to which the switch-bridge is pivoted.

4 5 Similar letters refer to similar parts throughout the several views.

My invention consists,essentially,in the operation of two cores orplungers movable in the magnetic field of a solenoid-coil and actedSerial No. 590,369. (No model.)

upon by a current passing through said coil and a switch-bridge actuatedby the operation of the cores or plungers to open or close the circuit.

In the specific device represented in Figs.

1 and 2 the beginning and end terminals are at A and II, respectively.The contact-terminals II and II are cup-shaped and filled with mercury.Contactis made between these and switch-bridge N by its ends G enteringthe mercury contained in said cups II and II. The cores I) and E areinserted in the upper and loweropenin gs of the non-magnetic tube L,which extends longitudinally through the center of coil .I and magneticjacket M. The upper core D' is prevented from entering entirely intotube L by being attached by pivot K to lever-arm n ,which supportsswitchbridge N. The lower core E is prevented during flow of normalcurrent from being drawn into the tube farther than the desired dis- 7otance by the counter resistance exerted by its weight. It is alsoprevented from being drawn entirely out of or away from the tube by theadjusting-screw S. The upper end of the core E is provided with anon-magnetic butt 0 to prevent it from sticking to the core I) when thetwo come into contact. The insulating substance Z may be employed asadditional insulation between coil J and non-magnetic tube L. The springP may be employed to break the force of the fall of counterbalance I),and also to retain it in the position to which it has been forced.

The action of the current passing through the coil is to exert a forcetending to suck or draw the core I) downward into the coil, drawing withit the switcl1bridge N, causing the contacts Gr to remain in themercury-cup terminals II and II. Thus the circuit is kept closed orlocked by the force of any normal current passing through it. A force isexerted in a similar manner upon core E, tending to suck or draw itupward into the coil, which force when exerted by normal current iscounteracted by the weight of the core, as above stated. Upon the flowof a predermined abnormal or excessive current, however, the

force exerted upon the core E, owing to its adj ustmenthereinafterdescribed,is su llieient to overcome the counter resistance of itsweight, and the core rises in a space of time in inverse ratio to thevolume of excessive current passing through the coil, the velocity ofthe cores movement constantly increasing until it strikes core D with amomentum sufiieient to drive core D upward and out of the coil. Theswitch-bridge to which core D is attached is carried with it, and thecontacts G are carried away from and out of the mercury cup terminals Hand H", thus opening the circuit.

Adjustment is effected with respect to the predetermined excessive flowof current necessary to cause an automatic break by regulating, by meansof :uljusting-screw S, the distance of the upper end of core E from thelower end of core i), also the approach of upper end of core E to themagnetic field with in the coil in connection with the weight of thesaid core, which may be diminished or added to by means of the movableweights. A looknut, as at Q, may be used to preserve the adjustment whenmade. R represents a grad uated scale to indicate the adj ustment.

The switch-bridge U is pivoted to the magnetic jacket M at C. Vhenactuated by the movement of core D or the pull of counterbalance li, itis carried over its pivot C and so held by force of gravity.

There are many cases in which it is desirable to open the circuit in theevent of a below-normal flow of current. As has been observed, thenormal i'low of current exerts a force upon core D to draw it downwardinto the coil. To this force there is a counteracting force exerted uponcore D tending to draw it upward out of the coil by the gravityv-sei-ght of the counterbalance B, which force a normal current issufficient to withstand. "\Vhcn, however, the How of current through thecoil falls below the predetermined minimum, the force exerted by it uponcore D is insufficient to withstand the force exerted by thecounterbalance B, which consequently falls and carries with it theswitch-bridge N and con tacts G away from mercury-cup terminals it andii, thus opening the circuit. Adjustment is effected with respect tosubnormal or minimum ll ow of current necessary to release core Dbyincreasing or diminishing the leverage power of counterbalance B bymoving it nearer to or farther from the fulciaim-pivot G by means of thescrew-thread upon stem T for said adjustment, as shown.

lVhile I have described my invention as embodied in the specific deviceshown in Figs. 1 and 2, it will be obvious to any one skilled in the artthat the device embodying my invention is capable of considerablevariation in detail of construction as well as mode of operation. Forexample, various forms of contact may be employed instead of mercurycupcontacts. In Fig. 3 the switch-bridge is provided with laminated copperbrushes G to contact with smooth flat-si'irlace contacts ll,

in which case the suck or downward pull upon core T) by flow of normalcurrent tends to increase and improve the contact between G and H. Asimilar result is accomplished by the form of construction shown in Fig.0, the laminated copper brushes being at ll instead of at G.

The knife-blade or clip contact is among other variations of contactthat may be employed.

Carbon-points g at the extremities of the switch-bridge X, in Fig. 3,are adapted to bear upon carbons 71, yicldingly attached tocontact-terminals ll and ii. for Iinal arcing.

The switch-bridge N, which is shown in Figs. 1 and 2 as pivoted tomagnetic jacket at G, need not be so pivoted, but may be dapted tofall'away when forced from its contact position, as shown in Fig. 6, orit may be so constructei'l as to be held by means of ratchets, as shownin Fig. in the farthest position to which it has been forced by theimpact of the cores. The ratchet device may also be employed inconjunction with. the pivoted bridge.

The core 1) need not be attached to ln-idge N or its lever-arm n in casesaid core is so constructed either by being widened at its upper end toa greater diameter than the diameter of the tube L, as shown at Fi (5,or by having a shoulder, as shown in big. '7, or where any othersuitable means be employed for preventing it from entering entirely intothe tube.

The core 1') maybe pivoted to magnetic jacket by an arm. independent ofswitchbridge or its pivot-arm. This is sometimes desirable in order torelieve the core and its counterbalance from outside influences, a, forinstance, the force which is imparted to the switch-ln'idge and itspivot-arm by the buoyancy of the mercury in the mercury-cup contacts.This has been found to interfere with the nice adjustment oi. thecircuitbreaker. In Fig. 7 the core 1) is pivoted to magnetic jacket byarm (7, which is rigid with counterbalance-arm l while switch-bridge Nis pivoted by arm 7t to same pivot C, but movingindependently of arm (7.Arm r7,being directly beneath arm n, has a preliminary movement beforeimpacting-arm I], as indicated by dotted line e.

The non-magnetic tube L, which extends longitudinallythrough the coiland the jacket in which the cores are movable, may be dispensed with bycovering the magnetic cores with a nonunagnetic material, leaving theends only exposed, or by covering such parts of the jacket or coil asmight be likely to come into contact with the cores with a nonmagneticmatcrial, or any other similar method of preventing the cores frommagnetically sticking to the jacket or coil. I have employed anon-magnetic tube simply as a convenient form of accomplishing this endand for the additional reason that it fur nishcs a guide for themovement of the cores.

IIO

Instead of the set-screw S for the purpose of supporting and adjustingthe core E a simple ledge or shelf may be employed to support the core,or a pin U may be used, as shown in Fig. 4, passing through the longitudinal slot Vin core E, in which case weights F may be attached to theextension Z of core E, as shown in said Fig. 4:, for purposes ofadjustment.

A fixed magnetic piece on may be inserted in the head of magneticjacket, as shown in Fig. 5, to reduce magnetic resistance and so thatwhen core E rises in the coil and impacts core 1), driving it upward,core E, having a diameter greater than that of the interior of saidmagnetic piece, adheres to its lower edge, thus preventing core D fromreturning to its normal position and closing the circuit.

Instead of the non-magnetic butt 0 being upon the end of core E the samemay be fixed upon the end of core D, or any equivalent means, movable orfixed between the two cores, may be employed to keep them frommagnetically sticking.

In the device specifically described adj ustment is effected by means ofregulating the distance between the cores and by adding to or lesseningthe weight of core E and adding to or lessening the leverage weight ofcounterbalance B. Additional adjustment may be effected by theemployment of springs or weights to act directly or indirectly uponeither or both cores, or springs may be employed entirely to substitutethe force of gravity, acting directly or indirectly, as through leverand counterbalance, upon the cores, in which case it is not necessarythat the cores have a vertical movement.

The circuit to be opened or closed may be either part of the circuitwherein the variation of current or voltage occurs or any other circuit.Instead of opening the circuit the switel1bridge may be adapted to becarried by the thrust of the cores or the pull of the counterbalance orsimilar force toward contact-terminals II and II of another circuit, asshown in Fig. 4, and so close it, or the terminals II and H may be inthe same circuit in which the variation of current or voltage occurs,and the effect of bridging of the terminals II and II is to cause ashort circuit, cutting out a portion of the line.

lVhat I claim as my invention, and desire to secure by Letters Patent,is

1. In an elec tromagnetic circuitbreaker the combination with the switchof two cores and a solenoid-coil, the cores movable in the mag neticfield of the coil and adapted to be actuated by the current passingthrough the coil to actuate the switch and the switclr bridge attachedto one of the cores, which is arranged and adapted to be actuated by theforce of a normal fiow of electric current to hold the terminals of theswitclrbridge in contact with the main contact-terminals with anefficiency in direct ratio to the volume of current flowing through thecoil.

2, In an electromagnetic circuit-breaker the combination with the switchof two cores, a solenoid-coil and a counterbalance, the cores movable inthe magnetic field of the coil and adapted to be actuated by the currentpassing through the coil, the switch-bridge attached to one of the coresand the counterbalance attached to the switch-bridge and adjusted andadapted to carry the switchbridge with its terminals toward or away fromthe main contact-terminals upon the How through the coil of apredetermined below normal current.

In an electromagnetic circuit-breaker the combination with the switch oftwo cores, a solenoid-coil and car 3011 contacts, the cores movable inthe magnetic field of the coil and adapted to be actuated by the currentpassing through the coil to actuate the switch, the carbon-points at theextremities of the switch-bridge adapted to bear upon the carbonsyieldiugly attached to the main contactterminals for final arcing.

i. In an electromagnetic circuit-breaker the combination withthe switchof two cores, a solenoid-coil and a ratchet device, the cores movable inthe magnetic field of the coil and adapted to be actuated by the currentpassing through the coil to actuate the switch, the ratchet deviceadapted and adjusted to hold the switch out of contact after having beenactuated.

5. In an electromagnetic circuit-breaker the combination with the switchof two cores and a solenoid-coil, the cores movable in the magneticfield of the coil and adapted to be actuated by the current passingthrough the coil to actuate the switch, with movable weights andset-screw as means of adjustment with respect to amount of excessivecurrent or voltage necessary to actuate it.

(3. In an electromagnetic circuit-breaker the combination with theswitch of two cores and a solenoid-coil, the cores movable in the magnetic field of the coil and adapted to be actuated by the currentpassing through the coil to actuate the switch, with movablecounterbalance as a means of adjustment with respect to minimum amountof current or voltage necessary for its actuation.

7. In an electromagnetic circuit-brcaker the combination with the switchof two cores, a solenoid-coil and a movable arm independent of theswitch-bridge, the cores vertically movable in the magnetic field of thecoil and adapted to be actuated by the current passing through the coilto actuate the switch, the upper core pivoted to the arm having amovement independent of the switch-bridge.

WALTER E. HARRINGTON.

Witnesses:

Jno. STOKES Aunts, \Vn. M. Sctrrir.

